Multi-compartment electrolytic cell



March 25, 1958 R. E. BRIGGS Filed Feb. 17, 1954 -MULTI-COMPARTMENTELECTROLYTIC CELL 3 Sheets-Sheet l 35 2 /1 25 26 z I 37 r #m I I: 34 393 I l l 30% i 24 a 36 24 r I i 33 )3 .25 26 INVENTOR ROBERT E. BRIGGSATTORNEYS March 25, 1958 R. E. BRIGGS MULTI-COMPARTMENT ELECTROLYTICCELL 3 Sheets-Sheet 2 Filed Feb. 17, 1954- ms T G v TW /W NR 1 B E r R Ew W Y B B W a M II\ 9] n V 3 ATTORNEYS March 25, 1958 R.-E.BRIGGS72,828,257

MULTI-COMPARTMENT ELECTROLYTIC CELL Filed Feb; 17, 1954 3 Sheets-Sheet 3WWW INVENTOR. ROBERT E. BRIGGS ATTORNEYS United. States Patent 2,828,257MULTI-COMPARTMENT ELECTROLYTIC CELL Robert E. Briggs, Abuza, Calif.

Application February 17, 1954, Serial No. 410,985

12 Claims. (Cl. 204263) This invention relates to an electrolytic celland to a method of electrolysis, and more particularly relates tomulti-compartment electrolytic cells or multi-compartment cellassemblies wherein a plurality of electrolytic effects is achieved.

This application is a continuation-in-part of my application No.285,613, filed May 2, 1952, for an Electrolytic Cell, now abandoned.That application was directed to an electrolytic cell having insolubleelectrodes and having one or more buffer compartments separated byporous or permeable diaphragms between an anode compartment and acathode compartment, or between a centrally disposed treatingcompartment and the anode and cathode compartments. Recent developmentshave made available ion exchange diaphragms which may be used to replacesome or all of the diaphragms in a multi-compartment electrolytic cellof the type there described. These diaphragms, for the most part, aresubject to dimensional expansion and contraction which, if not providedfor in the, type of mounting utilized, may readily destroy theusefulness of the diaphragm.

According to this invention there is provided a novel electrolytic cellstructure which provides for the mounting of diaphragms which may or maynot expand or contract under the influence of a liquid to be treated. Aplurality of frames is provided for receiving thevarious diaphragms, andthe frames are adjustably mounted so as to permit the diaphragms to beeither loosely held or tightly clamped therebetween. The frames arefurther constructed so as to permit easy and convenient filling of thevarious compartments and are so arranged as to make possible any desiredpath of flow of the liquid to be treated, or of the anolyte or catholyteutilized in the cell.

Where three compartment electrolytic cells are utilized for suchapplications as water softening, a precipitation of hardness compoundsoccurs in the highly alkaline catholyte of the cathode compartment. Thissituation also obtains where ion exchange resin diaphragms are used andtends to foul the cathode compartment and necessitate frequent shutdowns for cleaning operations.

According to this invention the acidic anolyte from the anodecompartment, instead of being discharged to waste, is flowed through thecathode compartment where it dissolves the previously precipitatedsolids and neutralizes the alkali there present to prevent-theprecipitation of more salts. This results in a diminution in electrodecompartment efiluent waste and also maintains a.

electrolytic cell wherein provision is made for mounting diaphragmswhich expand and contract under different operating conditions.

2,828,257 Patented Mar. 25, 1958 It is a still further object of theinvention to provide a multi-compartment electrolytic cell wherein equalliquid pressures are maintained outside and inside of the variouscompartments in such a way that leaks or mixing of the segregated andconcentrated or depleted electrolyte solutions in such compartments isminimized or becomes non-existent,

It is afurther object of the invention to provide a process ofelectrolysis ina three or more compartrnented electrolytic cell whereinprovision is made to prevent fouling of thecathode. compartment throughthe precipitation of salts. f1,

It is a still further object of the invention to provide such a celland'pr ocess which is suitable for purification or demineralization ofwater or other liquids on a large scale. I

' It is a still further object of the invention to provide such a cellwhich is also useful in the concentration of various selected chemicals.

Further objects and advantages of the invention will become clear uponreference to the following drawings wherein: v Figure lis-a'horizontalsectional view of a cell constructed according to thisinvention; v 1 Figure 2 is a side elevational view of the cell of Figure1;

Figure 3 is an end elevation of the cell of Figure 1;

Figure 4'is a vertical cross-sectional view of a modified form of cell;j

Figure-5 is a partial plan view of a corner of a cell which is amodification of the cell shown in Figure 1; 1

Figure 6 is a vertical sectional view showing a modified type of cathodeassembly;

Figure 7 is a horizontal section of the frames and diaphragms in anexpanded position;

Figure 8 is a vertical section of the diaphragms and frames of Figure 7taken on line 88 of Figure 7;

Figure 9 is a side elevational view of a frame and diaphragms as shownin Figures 7 and 8;

Figure 10 is a vertical cross section of the frame and diaphragm shownin Figure 9 taken on the line 10-40;

Figure 11 is a vertical section of the frame and diaphragms shown inFigure 9 taken on the line 11-1-;'

Figure 12 is a vertical sectional view of a frame suitable'for mountinga large number of diaphragms; and

Figure 13is a horizontal sectional view of a clamping arrangement foruse with a plurality of diaphragms.

Referring more particularly to the drawings, there is shown in Figure 1a cell indicated generally at 10 consisting of a tank 11 having sidewalls 12 and end walls 13. Mounted within the .tank 11 is a plurality ofskeletal frames 14 which have interleaved therebetween a plu rality ofdiaphragms 15.

Theframes 14 may be supported upon a support 16 having downturnedflanges or feet 17 which are supported on the bottom 18 0f the tank 11.At the outer faces of the outermost frames are located a pair of metalcompres sion plates 19 which may be of iron or steel, or other suitablemetal, and may serve both as outside compartment walls andas cathodes.Intermediate the innermost frames is located an anode support frame 20which has horizontal slots 21 in the top thereof for the accommodationof a plurality of anodes22. The anodes 22 may be formed of any suitableacid resistant material, a sheet or plate of compressed graphite orcarbon being preferred. The anodes 22 may be maintained in position bymeans of a plurality of pegs 23 which pass therethrough and whichsupport the anodes in the anode frame 20.

Pressure may be applied to the compression plates 19 by means of aplurality of compressionscrews 24 which a screw threadedly engagestandards 25 which may .be so 'cure'd to'the tank walls 12 by''any'suitable ma'n sueh" as by welding. The compression screws 24 may beprovided with suitable actuating handles such as the wheels rectangle,as would be represented by one half of the frame shown inFigure 9.Figure 9 represents a type of framewhich is suitable for supportingapair 'of 'diaphragms which are to be used as a single wallfor onecompartment of "a cell. The diaphragrnsmaybeadjustably supported thereonby means of a plurality of pegs 27 which matinglyengage a plurality ofapertures 28 in the adjacent frame, as is best seen in Figures 7 and"8to' be discussed more fully hereinafter.

Inlet and outlet connections may be as varied as the application towhich the electrolytic cell.is applied. In the embodiment of Figure 1,outlet connections for the various compartments are provided by means ofa'plu rality ofpipes 29 passing through packing glands 30in the 'endwall 13 of the tank 11. Such pipes are so aligned as to mate withapertures in the ends of the frames '14 whensaidfrarnesare in theircompressed position, the

connection between the end-'of the pipearid the'apei'ture tieing eitlierbyway of'friction or byway of screw threads. Since the design of thecell is such that liquid pressure inside and outside of'the variouscompartments is substantially equah it isnot necessary to providefittings to resist large pressures, although this may bedOi'le'ifdesired i lri' inlet coniiection31 having a control valve- 31a isprovided'in'thejleftmost tank'wall '13 annja drain'line 32d is connectedthereto through a valve- 32. Inlets to the compartments defined by thevarious framesmay be through orifices 42, 43, 44, 45 and 46 provided in'the tops 7 of frames 14, and where desired capillary tubes may belaced-imam orificesto provide anaccurate c'ontrol of electrolyte-'fio'w. v V g 7 With the-compression screws 24 released' at the time thetank is filled, all compartments will become filledand thediaphragmabei-rig looselyheld, will be allowed toexpandorcoritract inresponse to the eifectof the electrolyte. Prior to operation,compression may 'beapplied to the screws 24 bririi'ging each frame intoliquid and; slip tight engagement-with itS -a S'SbCi ated diaphragm '01compress'ion 'plate so"asto'forrn flow 'channels in the spaces boundedonthefsides 'by the diaphragms 'an'd on 'the top, bottom=and endsibyftheframes.

' The'cell shown inFigu'r'es 1 through '4 maybe used e'itheffo'rfthepurification of water fiow'in'g'throughcomp'a'rtinents 117 and 118 orfor the concentration of desired chemicalsin compartments 119, 120, 121and'122. De-

mineralization v'v'ill i always occur i in compart ments -117 and 118where non-selective barriers are used'while with selective barriers the'e'lfect will be determinedby the partiemarbarrier arrangement. Wherenon-selective barriers or diaphrag'r'ns are used and the purpose is'demineralization, as in large scale waterpurification, the compartments119,120,;121' and-"122 are preferably utilized asbufier compartments inthe manner described'in my aforemention'ed copending application285,613. When 'thus' utilized there is no waste removal from thesecompartments and this'is the type 'of use depicted in Figures 1 through4. 'Where'ion concentration is the desired effect however, and whereperm-selective barriers or diaphragms are' u'sed, thesefcompartm'entsmay be utilized'as the concentra'ting compartmentsand'must'be providedwith out lets similar "to the outlets provided in the othercompartments. It will beappreciated that the number" and loca- 'tion'-of eutlets'fi11 cells such asare shownin Figures 1 .th'ro1rgh' '4 viiibejditatd primarilyby'the particular ef- 7 feet to be aclrievediand'such varying arrangements are within the purview of this invention'valvingaction,shown diagrammatically asvalves 35 and 36, which might beV-weirs in the atmospheric pressure embodiment of the invention shown inFigures 1, 2 and 3. Suchweirs in pipes 33 and 34 would determinetheliquid level in the tank. Anolyte' and 'catholyte waste may bedischarged throughpipes 38 3sa and 40 which are below the electrolytelevel in the tank and in the respective compartments. Because of thisdifference in head these waste discharges may be controlled by theinsertion of properly selected capillary tubes in the discharge pipes,tubesofan inside'fdiameter of twototive millimeters usually beingsuitable; 'In addition'to these capillary discharge orifices, there:maytalso be provided, or there maybe alternatively provided, wastedischarge outlets 37, 39 and 41 which. are at the same level :as thedemineralizedliquid outlet 39. Control of thewaste' discharged throughpipes'37, 39 and 41'niay be-e'fiected by control valves in the inletorifices 42, 43, 44, 45, 46h It isa feature of the invention'that thefdesi'g'n provides for, substantially equaLpressures inv allcoiiipa'rtmer'its of the .cllso thatleaks or miXirig of the segregatedelectrolyte solutions is: minimized;

Whilethe cell shownin Figuresd, 2 and 3 operates at atmosphericpressure, lit is also possible to .utilize cells operating at higherpressures, and the tank shown in Fi'g'ure'4 is designed with this end inview. This cell is eoiis'tfucted in a manner similar to that shown inFigure l and'like reference numerals are utilized forcorrespondingpa'rts. The cell of Figure 4 differs from the celllofFig'iifel in thatit istprovided with a cover 47 which makes possible theapplication of pressure to the system The inlet' and outlet orifices maypass through pipes similar to those shown in Figures 1 and 3, but inthis instance each outlet orifice must be supplied with some type ofthrottle valve. Inlet pressure may generally be of the order of 10pounds per square inch for the pan.

7 electrical insulating material, such .as wood treated with awaterlresistant varnish or other water resisting coating orimpregnatingcompound "Diaphragm material is unlimitediand may includeiouexchangeorselective barriers or .butfe'r zones. With :some diaphragm materialsgaskets such as-gum nibberorsneoprene maybe requiredvor'; in thealternative, the edges of the-diaphragms may be treatedor coated with-anonhardening caulking compound. "Diaphragms of. a selfnsupportingcharacter suchas wood veneer, porous/ceramics or-the like.may rest "uponthe snppor'tfimember 1 6-and @may be brought into alignment betweenspacerLframes 14-and the compressi-on,plates"19.

Diaphragms ofua non-self-supporting character may be 7 hung from thedowel pins 27 as shownin Figures 7 and 8. When utilizing-such-dowelpinsthe diaphragms may be. provided with elongateduholes 48 which willpermit the desiredzexpansionyor contraction of-the diaphragms while'suspendedfrom-the "dowelpins 27c Certaindiaphr agms may require acombination of the two'means of suppert;

' Thecompressionplates19 may'beof iron orsteeland may serveooth ,as theouter compartmenf 'walls and as the cathodes of the cell. An alternatemethod if install-e ingcathodes is shown in Figure 6 wherein there issupplied an additional frame 49 between the outermost diaphragm 50 andthe compression plate 19. The frame 49 supports a foraminous cathode 51which may be formed of any conducting material which is resistant toattack by alkalis. Iron is entirely satisfactory and a piece of ironhardware cloth has been illustrated, although perforated or continuoussheets of iron or other alkali resistant metal such as nickel orstainless steel or sheets of carbon or compressed graphite may beemployed.

Whereas the cell of Figure 1 utilizes discharge connections which passthrough packing glands directly into the compartment forming frames,there isshown in Figure 5 an alternative method for providing outletconnections which may be utilized where the tank is sufliciently largeto provide space between the ends of the frame and diaphragm structureand the tank wall. Thus there is shown in Figure 5 a tank 52 having aside wall 53 and an end wall 54. A plurality of frames 55 supports aplurality of diaphragms 56 to foirn the various cell compartments.Compression screws 57 are provided as in the embodiment of Figures 1through 4.

In this embodiment of the invention each of the compartment formingframes from which it is desired to remove an effluent is provided with adischarge pipe 58 which has attached thereto a section of flexibletubing 59. The tubes 59 may be made of any suitable material which isresistant to the particular liquid being carried, many types of plasticor rubber tubes being satisfactory. The tubes 59 are connected at theiropposite ends to couplings 60 which pass through the tank wall 54 andemanate as pipes 61.

While the sectional view depicted by Figure 1 shows diaphragms whichextend the full length of the frames, it will frequently be foundnecessary to utilize diaphragms of smaller dimensions, since many of theion exchange diaphragms now available cannot be formed in large sizes.When the use of such small size diaphragms is necessary, a divided framesuch as that shown at 62 in Figure 9 may be desirable. The frame 62consists of a pair of horizontal frame members 63 and 64 and of a pairof vertical end frame members 65 and 66. Intermediate the verticalmembers 65 and 66 is a spacing member 67 which provides a bearingsurface for the junction of two diaphragms 68 and 69. Flow aperturesmaybe provided in the vertical portions of the frame member, that is tosay, an inlet aperture may be provided at 70 in the vertical member 65while connecting apertures 71, 72 and 73 may be provided in the spacingmember 67, as is best seen in Figures and 11.

While the cell shown in Figures 1 and 4 is shown as connected for onepass electrolyte flow, it is also possible to provide for sinuous orsnake-path fiow by providing the necessary connections within the tank.Thus,

referring to Figures 7 and 8, there is seen a plurality of frames 74, 75and 76 which support diaphragms 77, 78 and 79. The frames and diaphragmsare shown in a separated position for the sake of clarity. The left edgeof the frame 76, that is the vertical member corresponding to the member65 in Figure 9, may be provided with an inlet pipe 80 which passesthrough an orifice of the type 70 shown in Figure 10. Likewise the frame74 may be provided with a discharge pipe 81 which may pass through asimilar orifice. At the outlet end of the frame 76 there may be provideda discharge fitting 82 which is inserted into an orifice in the upperportion of the vertical member 66, as is shown in Figure 8. The frame 74may be further provided with an inlet fitting 83 in its lower edge as isshown in Figure 8. The fittings 82 and 33 may then be connected by asuitable piece of flexible tubing 84 of rubber or some suitable plasticmaterial. V

In Figure 12 there is shown a frame member which may be used where alarge cell is desired but where diae phragms are not available in largedimensions. Thus,

there is shown a frame member 85 which consists of vertical edge members86 and 87 and of horizontal edge members 88 and 89. Within the edgemembers 86, 87, 38 and 89, there are provided horizontal spacing members90 and 91 and vertical spacing members 92 and 93.

Suitable orifices 94, 95, 96, 97, 98, 99, 100, 101, 102 and 103 may beprovided in the members to obtain the desired flow. In the embodimentshown in Figure 12 a sinuous flow is obtained in the compartment formedby the frame 85. While the frame 85 has been shown as essentiallysquare, it will be obvious that a vertically elongated frame may beobtained, as by cutting the frame 85 along the line A-A in Figure 12, ora horizontally elongated frame may be obtained by cutting the frame 35along the line B-B of Figure 12. The vertically elongated cell structuremay be utilized where it is desired to conserve floor space whereas thehorizontally elongated cell results in very convenient diaphragmplacement and general servicing and may be used where larger areas offloor space are available. It will be readily appreciated that with thetype frame shown in Figure 12 any desired flow pattern may be secured bythe proper placement of the flow orifices in the spacing members.

In Figure 13 there is shown a means for joining compartment frames anddiaphragms where it is desirable to use a plurality of such frames in anextended horizontal flow cell, particularly where it is desired to treatwater on a large scale. through which passes compression screws 105 toengage with spanner blocks 106. For example, a block spans the edges ofcompression plates 107 and 108 which in turn engage the vertical endmembers 109 and 110 of frames 111 and 112. Diaphragms 113 and 114 may beheld in position by the frames 111 and 112. Suitable mating orifices 115and 116 may be provided in the vertical members 109 and 110 in order toprovide for flow between the adjoining compartments.

Cells constructed according to the invention make it possible to utilizesubstantially equal liquid pressures in the different compartments andin the space between the compartments and the tank walls, and thisresults in a minimizing of leakage and contamination of the variousliquids. The particular structure shown makes possible the provision ofsimple orifice flow passages within the frame members so that tubing orpipe connections are not required as conduits from one compartment toanother. Compartment frame members may therefore be of very smallthicknesses and the inlet and outlet channels may be provided throughthe compression plates 19, which may also serve as the cathodes.

In previous electrolytic treatment cells utilizing ion exchangediaphragms or barriers, the type of flow utilized has been of a parallelnature through a plurality of parallel compartments so as to obtain amaximum current efficiency. The flow of electrolyte in the electrodecompartments has been of a similar nature and has either been dischargedto waste where demineralization was the object of the process, ordelivered to collecting tanks where chemical concentration was theobject. Under either of the two foregoing processes, the high alkalinityin the cathode compartment results in the precipitation of shutdown ofthe cell for clean out of the compartment.

' treated, the discharge from the anode compartment of It is a featureof the present invention that where hardness compound precipitates arenot desired as an aid to removing undesired compounds from the liquid tobe the cell is fed to the cathode compartment to there dissolve suchprecipitates and to prevent the formation of further precipitates. Thisresults in a material saving' There is thus shown a tank wall 104 i inelectrieypowerand. results-inaphigher output from, the; cell due to the.elimination of shutdown; periods for; the'purposeof.cleaning-thecathodezcompartment; 'Wheredemineralization is, the object,there is alsoa substantial v savingin the amountof liquid discharged,aswaste.

Whereas various structures have been shown and various: methodsdiscussed: in connection with the present invention, these have been. byway of-- illustration only,- theinvention beinglimited solely by theterms'andspirit of the appended claims.-

I claim:

1. In an electrolytic-cell assembly; ofsubstant-ially vertical aperturedefining frame members arranged in said tank: in substantially parallel;relationship, a plurality of. substantially vertical iong permeablediaphragms interleaved. between said framet mem'bers; so as, to overliesaid apertures, the top portieu axqfi saidframe members havingsupporting element-s} attached thereto and extending toward an adjacentframe memberand said diaphragms having openings receiyingsaid supportingelements and of greatercross-sectional areathan said supporting elementsso-that said.diap hragms may be freely suspended between said frame;members andmay expand and contract therebetween; releasable clamp meansattached to said tank for urgingsaid framemembers. into liquid tightengagement withi saidz; dia-- phragms. to causesaid. diaphra-gms andframe-members;

to define. liquid. tight compartments Within said apertures andinletand-outlet means; in atleastoneof; said frame, members for flow ofliquid throughgthe aperture defined? by said frame member.

2-. In-an electrolytic cell assembly; a tanle azplurality ofisubstantially vertical aperture defining frame members arrangedin saidtankin substantially parallel:;relation-. ship, apluralityofsubstantially vertical ion; permeable diaphragms interleavedbetween said frame members .so as to overlie said apertures-,the,toppor'tionsof said. frame members having supporting .elementss attachedthereto and extendingtoward an adjacent-frame member and said diaphragmshaving openings; receiving said sup.- porting elements and of greatercross-sectional areaithan said supporting elements; so that said.diaphragm's; may be freely" suspended between said frame, members..-andmay expand and contract therebetween,.;a..pair of come pression. plates:substantially parallel: to Lsaid. :diaphragms' and overlying theapertures; in; the;f,outermostof said: frame membersreleasableaclampmeansattaelnedv to said tank fQ1T urging said: compressionplates:towards one anether'w as o press aid fr memi mhers into liquid tightengagement withasaid-diaphragms to oa-.u'se:said diephragms frame,members I and: compression :pl-ates; .to: define separate;liquid;tightcompartments withinsaid aper tures, andinlet -andoutlet-means in-at-Vleast' one; ofesaid; frame members;- for; flowqofliquid; throughpthegaperture defined by saidframe-member.

3. A cell-assembly as set forth in;claim:2 whereincsaim pluralityofdiaphragmsucompriseian even. number. and wherein the centerm'oststpairiof"diaphragms enclose an anode", said compression plates serving' -ascathodes;

4; A cell assembly asset'- forth in claim '3 wherein at least twoofrsaid ic ompart'ments onopp'ositesidesof said anode are; completelyenclosed" buffer comp artm'ents'.'.

5. A cell assembly asset'forthiri'claimfZ whereirf said releasable clampmeans comprises screws extending through and threadedly. engagingsaidl'tank. and having.-.

ends bearing against sfai'dicornpression plates.

6. A cell assembly asset forth. in wherein said inletmeans isand-orifice: establishing. direct. communication between said. tanlgnandthe aperture. definedxb'y said frame member, said outletQmeanst-includes,an: orifice and' a conduit, establishing,commnitiieationfrom said aperture.

efi ne lby said frame-1 member .to; the. exterior. of said tank andwherein a capillary tube is positioned in at a tank, a plurality 7'.A.cell assembly as set forth in claim 2 wherein said supporting elementscomprisera plurality of pegs extending: fromoneframe member throughelongated apertures in said' diaphragms and. into mating. openings inan-:adjace'nt framemember.

8..An electrolyticvcell assembly, comprising: a tank, a first series.of.frame members in saidtank arranged in face-to-face relationtoveachother; each of said frame members" having. top. and bottom andside members defining. .an aperture therebetween, said frame members;

having. their; side. membersv positioned substantially yertically insaid tank, a secondseries-of framejmernbersim said tank arranged. inthesame. relation to each: other and: to said tank as: said first. series(of frame members: and having side. members. adjoining side membersmf:saidr first series. ofaframe members, aplurality of-.inn-p er mea-.

bled-iaphragms. interleavedrbetweenthe faces. of corre-. sponding..frame members. ofeach series soas to. overlie. the apertures defined bythese frame members; a pluralityof compression. plates, eachengaging anoutermost-frame member. of. eachhof' said series, the edges. of; saidcompressionplates for adjacent frame members; being in adjoiningrelationship, means for spanning the, adjoining; edgesofisaidcompression plates, adjustable clamp means attached, to, said tanlc:opposite, saidmeans for spanning. said I compression. plates and.engaging, saidmeansto thereby urgesaidcompressionplates towardsaicLfrarnes and. clamp: said frames into liquidatight. engagementwithsaid diaphragms to cause said diaphragms'and framemembers to defineliquid-tight compartments-.-.Within said apertures, the adjoining sidemembersof saidseries-ofj frame members :having mating orifices-forliquid; flow betweencompartments formed by, saidv frame" members,andmeans forcontrolled flow of liquid from said tanlg through atleastone set; of compartments defined by-' frames having adjoiningsidemembersa 5 9. A cell assembly as setxforthain claim 2=whereirrsaidgframemembers anddiaphragms define arr-anode com partment and a cathode.compartment each-having inlet and outlet means and-wherein theanodecompartment. outlet means is connected to thecathodencompartmentinlet means. a a

10. In an electrolyticv cell assembly; a tank; aplurality of framemembers inasaid'tank, eachsaid framemem ber having top, bottom, sideand: interiondividing membersv defining at least;two* aperturestherebetween, said frame members having-their side members positionedsubstantially vertically in. said tanlc and having their topgand bottommembers arranged in;-substantially-parallel.relaa tionship' in 'saidtank, said top members; havingsupporb. ing elements at ta ohedi theretoand-extending; towardv an adjacent frame member; ion;permeablediaphragms dis-- posed between said frame members, saiddiaphragms; having p n eei i easaid ppo in 'il m t and r r ect na jea-than s d suppo ments so; that said diaphragms may be freely suspendedbetween saidframe--membersr-and may expand. and con: tract;therebetween; apair; of compression plates engaging e-ou mos am -mem es, ju abl d mn me attacheditosaid tanla oppositesaid compression platesand.

engaginggsa-id plates-for urging saidplates toward. each other tag-clampsaijd'top -andbottom and side members into qu d tightv ageme th: s i apasmsr id. di p a sa ndv n d o t m d s e rsd finr ing A liquid tightcompartments-, andinlet and outlet; means iuat least one ofsaidframemembers for flowof liquid through theapertures definedsby. saidframemernber.

' .11, A cellassemblyas. set forth in. claim. 10- wherein said inlet andoutlet means comprise orifices in said fr ame members andwhereinfiowopenings are provided through said .interioi -dividing members. 7

12. A cell assembly as set forth in claim 10 wherein 9 r 10 each. pairof frame members engages and supports there- FOREIGN PATENTS between atleast a pan of dlaphragms. 682,703 Great Britain Nov. 12 1952 ReferencesCited in the file of this patent 58.5596 Germany 1933 UNITED STATESPATENTS 5 OTHER REFERENCES 1,107,258 Burdett Aug. 18, 1914 Rohm & Haas:Amberplex Iron Permeable Mem- 1,297,157 Harris Mar. 11, 1919 branes(1952), pp. 19 to 23. 2,251,083 Theorell July 29, 1941 Langelier:Journal of the American Water Works 2,689,826 Kollsman Sept. 21, 1954 10Association, September 1952, pages 845 to 848.

1. IN A ELECTREOLYTIC CELL ASSEMBLY A TANK, A PLURALITY OF SUBSTANTIALLYVERTICAL APERTURE DEFINING FRAME MEMBERS ARRANGED IN SAID TANK INSUBSTANTIALLY PARALLEL RELATIONSHIP, A PLURALITY VERTICAL ION PERMABLEDIAPHRAGMS INTERLEAVED BETWEEN SAID FRAME MEMBERS SO AS TO OVERLIE SAIDAPERTURES, THE TOP PROTIONS OF SAID FRAME MEMBERS HAVING SUPPORTINGELEMENTS ATTACHED THERETO AND EXTENDING TOWARD AN ADJACENT FRAME MEMBERAND SAID DIAPHRAGMS HAVING OPENING RECEIVING AREA SUPPORTING ELEMENTSAND OF GREATER CROSS-SECTIONAL AREA THAN SAID SUPPORTING ELEMENTS SOTHAT SAID DIAPHRAGMS